What is St. Elmo’s fire phenomenon?

Answered by James Porterfield

St. Elmo's Fire is a fascinating natural phenomenon that occurs when the atmosphere becomes highly charged with electricity, creating an intense electrical potential between an object and the surrounding air. This phenomenon can occur when an aircraft is flying through heavily charged skies, resulting in a stunning display of plasma discharges.

Imagine being on an aircraft, flying through a stormy sky with dark clouds and thunder rumbling in the distance. Suddenly, you notice a peculiar phenomenon taking place. The tips of the aircraft's wings and other pointed objects start to emit a glowing, bluish-white light. This ethereal glow seems to dance and flicker, creating a mesmerizing spectacle for those fortunate enough to witness it. This is St. Elmo's Fire in action.

The name “St. Elmo's Fire” originates from sailors who observed a similar phenomenon on the masts and rigging of their ships during thunderstorms. They believed it to be a sign of protection from St. Elmo, the patron saint of sailors. Today, we know that this phenomenon occurs due to the build-up of electrical charge in the atmosphere.

So, how does this phenomenon actually happen? When an object, such as an aircraft, moves through the atmosphere, it can create friction with the air molecules. This friction can lead to the transfer of electrons between the object and the air, resulting in an electrical charge imbalance. When the electrical potential becomes strong enough, it causes a discharge of plasma, which is the glowing light we see as St. Elmo's Fire.

The glowing light of St. Elmo's Fire is a result of the excited electrons colliding with the gas molecules in the air. These collisions cause the gas molecules to emit light at specific wavelengths, giving it the characteristic bluish-white color. The intensity and visibility of St. Elmo's Fire can vary depending on the atmospheric conditions and the strength of the electrical charge.

While St. Elmo's Fire is a captivating sight, it is important to note that it is generally harmless. However, it may indicate the presence of an electrical storm, which can pose risks for aircraft and other objects in the vicinity. Pilots are trained to be aware of the weather conditions and take necessary precautions to ensure safety.

In my experience as a sommelier and brewer, I have not personally encountered St. Elmo's Fire. However, I have had the opportunity to learn about it through various scientific and historical accounts. It is truly a remarkable natural phenomenon that showcases the power and beauty of electricity in our atmosphere.

To summarize, St. Elmo's Fire is a mesmerizing phenomenon that occurs when the atmosphere becomes highly charged with electricity, creating an electrical potential between an object and the air. This can be observed when an aircraft flies through heavily charged skies, resulting in a spectacular display of plasma discharges. While it is generally harmless, it serves as a reminder of the dynamic and awe-inspiring nature of our atmosphere.